The present invention relates generally to hair cutting devices having a bladeset including a moving blade reciprocating relative to a stationary blade and a drive system for powering the bladeset, and more specifically to hair clippers or trimmers used for cutting hair of humans or animals.
Conventional hair cutting devices using a rotary drive system, such as hair trimmers and clippers typically include a drive member powered by the output shaft of the motor. For the purposes of this application, the terms “hair cutting device”, “hair clipper” and “hair trimmer” are considered interchangeable. The drive system converts rotary motion generated by the motor into linear motion in the form of the reciprocating moving blade relative to the stationary blade.
In most drive systems, a driving end of the drive member follows an arcuate or semi-arcuate path as it engages the moving blade of the bladeset. In this case, the term “semi-arcuate” refers to systems where at least part of the working stroke of the driving end follows an arcuate path. One such semi-arcuate conventional drive system employs a resilient parallelogram movement of the drive system. As such, the driving end moves in and out of engagement with the moving blade at least once during each revolution of the output shaft. In time, operational conditions, including heat and friction, combine to cause wear and deterioration of the driving end of the drive element. Such wear decreases operational efficiency of the clipper and often increases operational noise.
Another operational problem of conventional hair cutting devices is that hair clippings tend to accumulate in the area of the bladeset. The accumulation, which is more severe when the hair is wet, impedes the efficiency of the cutting device, since the unit does not move as quickly through the subject's hair. This condition also is more pronounced when clipping or shearing animal hair.
Still another operational problem of many conventional hair cutting devices is that the on/off switch is typically located on the top or side of the housing, where it is often accidentally actuated by the user during use. This may interfere with the cutting operation, especially when the operator is in the midst of styling, and prefers minimum interruption.
Thus, there is a need for a drive system for a hair cutting device which addresses the above-identified problems of conventional units.